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authorLinus Torvalds <torvalds@woody.linux-foundation.org>2007-05-11 09:57:16 -0700
committerLinus Torvalds <torvalds@woody.linux-foundation.org>2007-05-11 09:57:16 -0700
commit853da0022023c046e0a5ccc51d427745f0c94de7 (patch)
treebc36f80f00aa11c3c239a80ecf04ba8238219ce8 /kernel
parent5884c40668a928bba017eaf54e2eb3c01c8a98e6 (diff)
parent0a4ff8c2598b72f2fa9d50aae9e1809e684dbf41 (diff)
downloadlwn-853da0022023c046e0a5ccc51d427745f0c94de7.tar.gz
lwn-853da0022023c046e0a5ccc51d427745f0c94de7.zip
Merge branch 'audit.b38' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/audit-current
* 'audit.b38' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/audit-current: [PATCH] Abnormal End of Processes [PATCH] match audit name data [PATCH] complete message queue auditing [PATCH] audit inode for all xattr syscalls [PATCH] initialize name osid [PATCH] audit signal recipients [PATCH] add SIGNAL syscall class (v3) [PATCH] auditing ptrace
Diffstat (limited to 'kernel')
-rw-r--r--kernel/audit.h13
-rw-r--r--kernel/auditfilter.c48
-rw-r--r--kernel/auditsc.c311
-rw-r--r--kernel/ptrace.c3
-rw-r--r--kernel/signal.c10
5 files changed, 290 insertions, 95 deletions
diff --git a/kernel/audit.h b/kernel/audit.h
index a3370232a390..815d6f5c04ee 100644
--- a/kernel/audit.h
+++ b/kernel/audit.h
@@ -83,6 +83,7 @@ struct audit_krule {
u32 field_count;
char *filterkey; /* ties events to rules */
struct audit_field *fields;
+ struct audit_field *arch_f; /* quick access to arch field */
struct audit_field *inode_f; /* quick access to an inode field */
struct audit_watch *watch; /* associated watch */
struct list_head rlist; /* entry in audit_watch.rules list */
@@ -131,17 +132,19 @@ extern void audit_handle_ievent(struct inotify_watch *, u32, u32, u32,
extern int selinux_audit_rule_update(void);
#ifdef CONFIG_AUDITSYSCALL
-extern void __audit_signal_info(int sig, struct task_struct *t);
-static inline void audit_signal_info(int sig, struct task_struct *t)
+extern int __audit_signal_info(int sig, struct task_struct *t);
+static inline int audit_signal_info(int sig, struct task_struct *t)
{
- if (unlikely(audit_pid && t->tgid == audit_pid))
- __audit_signal_info(sig, t);
+ if (unlikely((audit_pid && t->tgid == audit_pid) ||
+ (audit_signals && !audit_dummy_context())))
+ return __audit_signal_info(sig, t);
+ return 0;
}
extern enum audit_state audit_filter_inodes(struct task_struct *,
struct audit_context *);
extern void audit_set_auditable(struct audit_context *);
#else
-#define audit_signal_info(s,t)
+#define audit_signal_info(s,t) AUDIT_DISABLED
#define audit_filter_inodes(t,c) AUDIT_DISABLED
#define audit_set_auditable(c)
#endif
diff --git a/kernel/auditfilter.c b/kernel/auditfilter.c
index 3749193aed8c..6c61263ff96d 100644
--- a/kernel/auditfilter.c
+++ b/kernel/auditfilter.c
@@ -311,6 +311,43 @@ int audit_match_class(int class, unsigned syscall)
return classes[class][AUDIT_WORD(syscall)] & AUDIT_BIT(syscall);
}
+static inline int audit_match_class_bits(int class, u32 *mask)
+{
+ int i;
+
+ if (classes[class]) {
+ for (i = 0; i < AUDIT_BITMASK_SIZE; i++)
+ if (mask[i] & classes[class][i])
+ return 0;
+ }
+ return 1;
+}
+
+static int audit_match_signal(struct audit_entry *entry)
+{
+ struct audit_field *arch = entry->rule.arch_f;
+
+ if (!arch) {
+ /* When arch is unspecified, we must check both masks on biarch
+ * as syscall number alone is ambiguous. */
+ return (audit_match_class_bits(AUDIT_CLASS_SIGNAL,
+ entry->rule.mask) &&
+ audit_match_class_bits(AUDIT_CLASS_SIGNAL_32,
+ entry->rule.mask));
+ }
+
+ switch(audit_classify_arch(arch->val)) {
+ case 0: /* native */
+ return (audit_match_class_bits(AUDIT_CLASS_SIGNAL,
+ entry->rule.mask));
+ case 1: /* 32bit on biarch */
+ return (audit_match_class_bits(AUDIT_CLASS_SIGNAL_32,
+ entry->rule.mask));
+ default:
+ return 1;
+ }
+}
+
/* Common user-space to kernel rule translation. */
static inline struct audit_entry *audit_to_entry_common(struct audit_rule *rule)
{
@@ -429,6 +466,7 @@ static struct audit_entry *audit_rule_to_entry(struct audit_rule *rule)
err = -EINVAL;
goto exit_free;
}
+ entry->rule.arch_f = f;
break;
case AUDIT_PERM:
if (f->val & ~15)
@@ -519,7 +557,6 @@ static struct audit_entry *audit_data_to_entry(struct audit_rule_data *data,
case AUDIT_FSGID:
case AUDIT_LOGINUID:
case AUDIT_PERS:
- case AUDIT_ARCH:
case AUDIT_MSGTYPE:
case AUDIT_PPID:
case AUDIT_DEVMAJOR:
@@ -531,6 +568,9 @@ static struct audit_entry *audit_data_to_entry(struct audit_rule_data *data,
case AUDIT_ARG2:
case AUDIT_ARG3:
break;
+ case AUDIT_ARCH:
+ entry->rule.arch_f = f;
+ break;
case AUDIT_SUBJ_USER:
case AUDIT_SUBJ_ROLE:
case AUDIT_SUBJ_TYPE:
@@ -1221,6 +1261,9 @@ static inline int audit_add_rule(struct audit_entry *entry,
#ifdef CONFIG_AUDITSYSCALL
if (!dont_count)
audit_n_rules++;
+
+ if (!audit_match_signal(entry))
+ audit_signals++;
#endif
mutex_unlock(&audit_filter_mutex);
@@ -1294,6 +1337,9 @@ static inline int audit_del_rule(struct audit_entry *entry,
#ifdef CONFIG_AUDITSYSCALL
if (!dont_count)
audit_n_rules--;
+
+ if (!audit_match_signal(entry))
+ audit_signals--;
#endif
mutex_unlock(&audit_filter_mutex);
diff --git a/kernel/auditsc.c b/kernel/auditsc.c
index 628c7ac590a0..e36481ed61b4 100644
--- a/kernel/auditsc.c
+++ b/kernel/auditsc.c
@@ -78,17 +78,15 @@ extern int audit_enabled;
* for saving names from getname(). */
#define AUDIT_NAMES 20
-/* AUDIT_NAMES_RESERVED is the number of slots we reserve in the
- * audit_context from being used for nameless inodes from
- * path_lookup. */
-#define AUDIT_NAMES_RESERVED 7
-
/* Indicates that audit should log the full pathname. */
#define AUDIT_NAME_FULL -1
/* number of audit rules */
int audit_n_rules;
+/* determines whether we collect data for signals sent */
+int audit_signals;
+
/* When fs/namei.c:getname() is called, we store the pointer in name and
* we don't let putname() free it (instead we free all of the saved
* pointers at syscall exit time).
@@ -114,6 +112,9 @@ struct audit_aux_data {
#define AUDIT_AUX_IPCPERM 0
+/* Number of target pids per aux struct. */
+#define AUDIT_AUX_PIDS 16
+
struct audit_aux_data_mq_open {
struct audit_aux_data d;
int oflag;
@@ -181,6 +182,13 @@ struct audit_aux_data_path {
struct vfsmount *mnt;
};
+struct audit_aux_data_pids {
+ struct audit_aux_data d;
+ pid_t target_pid[AUDIT_AUX_PIDS];
+ u32 target_sid[AUDIT_AUX_PIDS];
+ int pid_count;
+};
+
/* The per-task audit context. */
struct audit_context {
int dummy; /* must be the first element */
@@ -201,6 +209,7 @@ struct audit_context {
struct vfsmount * pwdmnt;
struct audit_context *previous; /* For nested syscalls */
struct audit_aux_data *aux;
+ struct audit_aux_data *aux_pids;
/* Save things to print about task_struct */
pid_t pid, ppid;
@@ -209,6 +218,9 @@ struct audit_context {
unsigned long personality;
int arch;
+ pid_t target_pid;
+ u32 target_sid;
+
#if AUDIT_DEBUG
int put_count;
int ino_count;
@@ -654,6 +666,10 @@ static inline void audit_free_aux(struct audit_context *context)
context->aux = aux->next;
kfree(aux);
}
+ while ((aux = context->aux_pids)) {
+ context->aux_pids = aux->next;
+ kfree(aux);
+ }
}
static inline void audit_zero_context(struct audit_context *context,
@@ -795,6 +811,29 @@ static void audit_log_task_info(struct audit_buffer *ab, struct task_struct *tsk
audit_log_task_context(ab);
}
+static int audit_log_pid_context(struct audit_context *context, pid_t pid,
+ u32 sid)
+{
+ struct audit_buffer *ab;
+ char *s = NULL;
+ u32 len;
+ int rc = 0;
+
+ ab = audit_log_start(context, GFP_KERNEL, AUDIT_OBJ_PID);
+ if (!ab)
+ return 1;
+
+ if (selinux_sid_to_string(sid, &s, &len)) {
+ audit_log_format(ab, "opid=%d obj=(none)", pid);
+ rc = 1;
+ } else
+ audit_log_format(ab, "opid=%d obj=%s", pid, s);
+ audit_log_end(ab);
+ kfree(s);
+
+ return rc;
+}
+
static void audit_log_exit(struct audit_context *context, struct task_struct *tsk)
{
int i, call_panic = 0;
@@ -973,6 +1012,21 @@ static void audit_log_exit(struct audit_context *context, struct task_struct *ts
audit_log_end(ab);
}
+ for (aux = context->aux_pids; aux; aux = aux->next) {
+ struct audit_aux_data_pids *axs = (void *)aux;
+ int i;
+
+ for (i = 0; i < axs->pid_count; i++)
+ if (audit_log_pid_context(context, axs->target_pid[i],
+ axs->target_sid[i]))
+ call_panic = 1;
+ }
+
+ if (context->target_pid &&
+ audit_log_pid_context(context, context->target_pid,
+ context->target_sid))
+ call_panic = 1;
+
if (context->pwd && context->pwdmnt) {
ab = audit_log_start(context, GFP_KERNEL, AUDIT_CWD);
if (ab) {
@@ -1193,6 +1247,10 @@ void audit_syscall_exit(int valid, long return_code)
} else {
audit_free_names(context);
audit_free_aux(context);
+ context->aux = NULL;
+ context->aux_pids = NULL;
+ context->target_pid = 0;
+ context->target_sid = 0;
kfree(context->filterkey);
context->filterkey = NULL;
tsk->audit_context = context;
@@ -1226,6 +1284,7 @@ void __audit_getname(const char *name)
context->names[context->name_count].name_len = AUDIT_NAME_FULL;
context->names[context->name_count].name_put = 1;
context->names[context->name_count].ino = (unsigned long)-1;
+ context->names[context->name_count].osid = 0;
++context->name_count;
if (!context->pwd) {
read_lock(&current->fs->lock);
@@ -1279,6 +1338,28 @@ void audit_putname(const char *name)
#endif
}
+static int audit_inc_name_count(struct audit_context *context,
+ const struct inode *inode)
+{
+ if (context->name_count >= AUDIT_NAMES) {
+ if (inode)
+ printk(KERN_DEBUG "name_count maxed, losing inode data: "
+ "dev=%02x:%02x, inode=%lu",
+ MAJOR(inode->i_sb->s_dev),
+ MINOR(inode->i_sb->s_dev),
+ inode->i_ino);
+
+ else
+ printk(KERN_DEBUG "name_count maxed, losing inode data");
+ return 1;
+ }
+ context->name_count++;
+#if AUDIT_DEBUG
+ context->ino_count++;
+#endif
+ return 0;
+}
+
/* Copy inode data into an audit_names. */
static void audit_copy_inode(struct audit_names *name, const struct inode *inode)
{
@@ -1316,13 +1397,10 @@ void __audit_inode(const char *name, const struct inode *inode)
else {
/* FIXME: how much do we care about inodes that have no
* associated name? */
- if (context->name_count >= AUDIT_NAMES - AUDIT_NAMES_RESERVED)
+ if (audit_inc_name_count(context, inode))
return;
- idx = context->name_count++;
+ idx = context->name_count - 1;
context->names[idx].name = NULL;
-#if AUDIT_DEBUG
- ++context->ino_count;
-#endif
}
audit_copy_inode(&context->names[idx], inode);
}
@@ -1346,7 +1424,7 @@ void __audit_inode_child(const char *dname, const struct inode *inode,
{
int idx;
struct audit_context *context = current->audit_context;
- const char *found_name = NULL;
+ const char *found_parent = NULL, *found_child = NULL;
int dirlen = 0;
if (!context->in_syscall)
@@ -1354,88 +1432,73 @@ void __audit_inode_child(const char *dname, const struct inode *inode,
/* determine matching parent */
if (!dname)
- goto update_context;
- for (idx = 0; idx < context->name_count; idx++)
- if (context->names[idx].ino == parent->i_ino) {
- const char *name = context->names[idx].name;
+ goto add_names;
- if (!name)
- continue;
+ /* parent is more likely, look for it first */
+ for (idx = 0; idx < context->name_count; idx++) {
+ struct audit_names *n = &context->names[idx];
- if (audit_compare_dname_path(dname, name, &dirlen) == 0) {
- context->names[idx].name_len = dirlen;
- found_name = name;
- break;
- }
+ if (!n->name)
+ continue;
+
+ if (n->ino == parent->i_ino &&
+ !audit_compare_dname_path(dname, n->name, &dirlen)) {
+ n->name_len = dirlen; /* update parent data in place */
+ found_parent = n->name;
+ goto add_names;
}
+ }
-update_context:
- idx = context->name_count;
- if (context->name_count == AUDIT_NAMES) {
- printk(KERN_DEBUG "name_count maxed and losing %s\n",
- found_name ?: "(null)");
- return;
+ /* no matching parent, look for matching child */
+ for (idx = 0; idx < context->name_count; idx++) {
+ struct audit_names *n = &context->names[idx];
+
+ if (!n->name)
+ continue;
+
+ /* strcmp() is the more likely scenario */
+ if (!strcmp(dname, n->name) ||
+ !audit_compare_dname_path(dname, n->name, &dirlen)) {
+ if (inode)
+ audit_copy_inode(n, inode);
+ else
+ n->ino = (unsigned long)-1;
+ found_child = n->name;
+ goto add_names;
+ }
}
- context->name_count++;
-#if AUDIT_DEBUG
- context->ino_count++;
-#endif
- /* Re-use the name belonging to the slot for a matching parent directory.
- * All names for this context are relinquished in audit_free_names() */
- context->names[idx].name = found_name;
- context->names[idx].name_len = AUDIT_NAME_FULL;
- context->names[idx].name_put = 0; /* don't call __putname() */
-
- if (!inode)
- context->names[idx].ino = (unsigned long)-1;
- else
- audit_copy_inode(&context->names[idx], inode);
-
- /* A parent was not found in audit_names, so copy the inode data for the
- * provided parent. */
- if (!found_name) {
- idx = context->name_count;
- if (context->name_count == AUDIT_NAMES) {
- printk(KERN_DEBUG
- "name_count maxed and losing parent inode data: dev=%02x:%02x, inode=%lu",
- MAJOR(parent->i_sb->s_dev),
- MINOR(parent->i_sb->s_dev),
- parent->i_ino);
+
+add_names:
+ if (!found_parent) {
+ if (audit_inc_name_count(context, parent))
return;
- }
- context->name_count++;
-#if AUDIT_DEBUG
- context->ino_count++;
-#endif
+ idx = context->name_count - 1;
+ context->names[idx].name = NULL;
audit_copy_inode(&context->names[idx], parent);
}
-}
-/**
- * audit_inode_update - update inode info for last collected name
- * @inode: inode being audited
- *
- * When open() is called on an existing object with the O_CREAT flag, the inode
- * data audit initially collects is incorrect. This additional hook ensures
- * audit has the inode data for the actual object to be opened.
- */
-void __audit_inode_update(const struct inode *inode)
-{
- struct audit_context *context = current->audit_context;
- int idx;
+ if (!found_child) {
+ if (audit_inc_name_count(context, inode))
+ return;
+ idx = context->name_count - 1;
- if (!context->in_syscall || !inode)
- return;
+ /* Re-use the name belonging to the slot for a matching parent
+ * directory. All names for this context are relinquished in
+ * audit_free_names() */
+ if (found_parent) {
+ context->names[idx].name = found_parent;
+ context->names[idx].name_len = AUDIT_NAME_FULL;
+ /* don't call __putname() */
+ context->names[idx].name_put = 0;
+ } else {
+ context->names[idx].name = NULL;
+ }
- if (context->name_count == 0) {
- context->name_count++;
-#if AUDIT_DEBUG
- context->ino_count++;
-#endif
+ if (inode)
+ audit_copy_inode(&context->names[idx], inode);
+ else
+ context->names[idx].ino = (unsigned long)-1;
}
- idx = context->name_count - 1;
-
- audit_copy_inode(&context->names[idx], inode);
}
/**
@@ -1880,6 +1943,14 @@ int audit_sockaddr(int len, void *a)
return 0;
}
+void __audit_ptrace(struct task_struct *t)
+{
+ struct audit_context *context = current->audit_context;
+
+ context->target_pid = t->pid;
+ selinux_get_task_sid(t, &context->target_sid);
+}
+
/**
* audit_avc_path - record the granting or denial of permissions
* @dentry: dentry to record
@@ -1918,15 +1989,17 @@ int audit_avc_path(struct dentry *dentry, struct vfsmount *mnt)
* If the audit subsystem is being terminated, record the task (pid)
* and uid that is doing that.
*/
-void __audit_signal_info(int sig, struct task_struct *t)
+int __audit_signal_info(int sig, struct task_struct *t)
{
+ struct audit_aux_data_pids *axp;
+ struct task_struct *tsk = current;
+ struct audit_context *ctx = tsk->audit_context;
extern pid_t audit_sig_pid;
extern uid_t audit_sig_uid;
extern u32 audit_sig_sid;
- if (sig == SIGTERM || sig == SIGHUP || sig == SIGUSR1) {
- struct task_struct *tsk = current;
- struct audit_context *ctx = tsk->audit_context;
+ if (audit_pid && t->tgid == audit_pid &&
+ (sig == SIGTERM || sig == SIGHUP || sig == SIGUSR1)) {
audit_sig_pid = tsk->pid;
if (ctx)
audit_sig_uid = ctx->loginuid;
@@ -1934,4 +2007,72 @@ void __audit_signal_info(int sig, struct task_struct *t)
audit_sig_uid = tsk->uid;
selinux_get_task_sid(tsk, &audit_sig_sid);
}
+
+ if (!audit_signals) /* audit_context checked in wrapper */
+ return 0;
+
+ /* optimize the common case by putting first signal recipient directly
+ * in audit_context */
+ if (!ctx->target_pid) {
+ ctx->target_pid = t->tgid;
+ selinux_get_task_sid(t, &ctx->target_sid);
+ return 0;
+ }
+
+ axp = (void *)ctx->aux_pids;
+ if (!axp || axp->pid_count == AUDIT_AUX_PIDS) {
+ axp = kzalloc(sizeof(*axp), GFP_ATOMIC);
+ if (!axp)
+ return -ENOMEM;
+
+ axp->d.type = AUDIT_OBJ_PID;
+ axp->d.next = ctx->aux_pids;
+ ctx->aux_pids = (void *)axp;
+ }
+ BUG_ON(axp->pid_count > AUDIT_AUX_PIDS);
+
+ axp->target_pid[axp->pid_count] = t->tgid;
+ selinux_get_task_sid(t, &axp->target_sid[axp->pid_count]);
+ axp->pid_count++;
+
+ return 0;
+}
+
+/**
+ * audit_core_dumps - record information about processes that end abnormally
+ * @sig: signal value
+ *
+ * If a process ends with a core dump, something fishy is going on and we
+ * should record the event for investigation.
+ */
+void audit_core_dumps(long signr)
+{
+ struct audit_buffer *ab;
+ u32 sid;
+
+ if (!audit_enabled)
+ return;
+
+ if (signr == SIGQUIT) /* don't care for those */
+ return;
+
+ ab = audit_log_start(NULL, GFP_KERNEL, AUDIT_ANOM_ABEND);
+ audit_log_format(ab, "auid=%u uid=%u gid=%u",
+ audit_get_loginuid(current->audit_context),
+ current->uid, current->gid);
+ selinux_get_task_sid(current, &sid);
+ if (sid) {
+ char *ctx = NULL;
+ u32 len;
+
+ if (selinux_sid_to_string(sid, &ctx, &len))
+ audit_log_format(ab, " ssid=%u", sid);
+ else
+ audit_log_format(ab, " subj=%s", ctx);
+ kfree(ctx);
+ }
+ audit_log_format(ab, " pid=%d comm=", current->pid);
+ audit_log_untrustedstring(ab, current->comm);
+ audit_log_format(ab, " sig=%ld", signr);
+ audit_log_end(ab);
}
diff --git a/kernel/ptrace.c b/kernel/ptrace.c
index 4d50e06fd745..ad7949a589dd 100644
--- a/kernel/ptrace.c
+++ b/kernel/ptrace.c
@@ -18,6 +18,7 @@
#include <linux/ptrace.h>
#include <linux/security.h>
#include <linux/signal.h>
+#include <linux/audit.h>
#include <asm/pgtable.h>
#include <asm/uaccess.h>
@@ -161,6 +162,8 @@ int ptrace_attach(struct task_struct *task)
{
int retval;
+ audit_ptrace(task);
+
retval = -EPERM;
if (task->pid <= 1)
goto out;
diff --git a/kernel/signal.c b/kernel/signal.c
index 34b7d6abce8f..364fc95bf97c 100644
--- a/kernel/signal.c
+++ b/kernel/signal.c
@@ -497,6 +497,11 @@ static int check_kill_permission(int sig, struct siginfo *info,
int error = -EINVAL;
if (!valid_signal(sig))
return error;
+
+ error = audit_signal_info(sig, t); /* Let audit system see the signal */
+ if (error)
+ return error;
+
error = -EPERM;
if ((info == SEND_SIG_NOINFO || (!is_si_special(info) && SI_FROMUSER(info)))
&& ((sig != SIGCONT) ||
@@ -506,10 +511,7 @@ static int check_kill_permission(int sig, struct siginfo *info,
&& !capable(CAP_KILL))
return error;
- error = security_task_kill(t, info, sig, 0);
- if (!error)
- audit_signal_info(sig, t); /* Let audit system see the signal */
- return error;
+ return security_task_kill(t, info, sig, 0);
}
/* forward decl */